17, 6 Trelease: Salt Requirements of Wheat Plants 589 
Concentration, atmospheres. 
QS: 10: (6°27 25 35 4.5 5ST 7.0 
700 
[| \ | Watertrequirement tops, SIT 
~ ~*~ ZHI 
sa, 
600 v 
500 
400 
| 23001 —% 
2200|— 
2/00 
2p00 : 
(900 gies 
(800 mane : 
) x, 71/ Water-requirement roots, SIV 
|700|\—+ me 
1600 oo \ Hox 
L500 **, 
1,400 5 * 
. if, +~ : 
1200 io 900, +~ t. 
, Mel Nc ae j 
1,100 aoe 
1,000 eae ea 
900 
Cubie centimeters per gram 
se 
Fie. 12. Graphs of average water requirement of tops and of roots for series IV. 
